Shipping containers are used throughout the world to ship goods as part of a global supply chain. Many shipping companies attach transmitting devices to shipping containers to either track their geographic location or for security purposes. This allows the shipping company to determine the geographic location of the container as it moves between the origination and intermediate or final destination points to determine whether the goods inside the shipping container are on time, late, or misplaced. For instance, the shipping container may have been misrouted shipping container or been placed on the incorrect transport ship to reach its intended destination. A misrouted may be indicative of a security breach that requires special attention. Further, communicating a misrouted shipping container condition to a shipping company and/or intended recipient of the shipment may better allow for planning purposes, especially in manufacturing. The advantages of tracking the position of shipped goods are many and therefore have become commonplace throughout the shipping industry.
Many shipping containers employ the use of a global positioning system (GPS) and a transmitter to communicate the whereabouts of the shipping container. The GPS associated with the shipping container receives signals from GPS satellites that allows the GPS to ascertain its coordinates. An identification indicia of the shipping container along with its calculated coordinates are then transmitted by the on-board transmitter to a remote receiver station or location where the identification indicia and coordinates are received. The identification indicia may be stored in memory located on-board the shipping container, or in an active radio-frequency identification device (RFID). A transmitter may store the identification indicia regarding the container in the RFID during manufacture or when shipping is initiated. The remote receiver station may employ algorithms to log the received data from the shipping container and communicate the data to another system or operator.
A common problem in each of these tracking systems is that the shipping container employs an active transmitting device that substantially increases the cost of the shipping container. Without an active transmitting device, the remote receiver station would not receive communications from the shipping container and thus not know if the shipping container reaches its intended destination points, is misrouted or is lost. Further, the active transmitting device requires its own power source that must be monitored and replaced as necessary. A shipping container will not transmit its identification indicia and location information if the power source is drained, thus causing the shipping container to in essence be lost in the supply chain. Also, the GPS satellite signals that communicate may not always be able to reach the shipping container, and thus the location information may not always be ascertainable. For instance, the shipping container may be contained inside a cargo hold, such as on a ship or inside a transport truck. The GPS satellite signals will be blocked from reaching the shipping container's GPS.